ACID

is an acronym used in databases to describe the properties associated with the input-output operations on the data.

• A: Atomicity: A transaction is a single unit. All or nothing. No data is discarded.
• A: Atomicity: Ex: deleting 3 rows should remove the 3 rows or none.
• C: Consistency: The integrity of the data and relationships is maintained after any transaction committed.
• C: Consistency: Ex: you can’t remove a user with associated receipts, invoices, etc.
• I: Isolation: Multiple transactions can happen in parallel without leading to inconsistency.
• I: Isolation: Ex: If two transactions change the same data, the change doesn’t affect each other’s data.
• I: Isolation: Databases, usually allow different levels of isolation.
• D: Durability: After a transaction is committed, no data can be lost for any reason.
• D: Durability: Ex: If a system failure happens, the committed transactions are guaranteed to remain.